The organic light-emitting diode (OLED) has been increasingly used as a high-performance display as a current-emitting device. The traditional passive matrix organic light emitting diode (Passive Matrix OLED, PMOLED) display needs a shorter single pixel drive time as the display size increases, thus needs to increase the transient current to increase power consumption. Meanwhile, the large current application will cause the overlarge voltage drop on the ITO line to result in that the OLED operating voltage is too high, thereby reducing the efficiency. The active matrix organic light emitting diode (Active Matrix OLED, AMOLED) display progressively inputs OLED current through the switch lines row by row and can solve these problems well.
However, the AMOLED display technology still possesses more obvious defects. Since the panel manufacture is not uniform, the threshold voltage, mobility and other electrical parameters of the respective driving thin film transistors are nonuniform. This nonuniformity will be converted into the current difference and the brightness difference between the OLEDs to result in uneven brightness among pixels and display differences. Although some of the compensation skills solve the influence of the threshold voltage, the cost is a complex compensation circuit to reduce the aperture rate of the pixel. The evaporation process in the panel manufacturing process leads to the property differences among the sub-pixels, such as differences of the cross-voltage and the luminous efficiency of the OLEDs or the luminous efficiency attenuation caused by the OLED device aging similarly causes the display differences among the pixels.